I want to predict the value of a scalar-field at the runTime using its at the previous two time-steps. In a mathematical expression, it can be expressed like F(n+1)=2*F(n)-F(n-1).
In openFOAM, I know that creatField can read and write the values in the running. So, the previous two time-steps maybe can read by IOobject from time-named folder. But, I don't want to write the field at all steps.
Are there some skills to realize this but no writing in every step?